Nonreversible steering mechanism



Jan. 9, 1934. F. c. cRAw NONEVERSIBLE STEERING MECHANjISM Filed ppn 4, 192s s sheets-sheet. 1

Jan. 9, 1934. F, CRAW 1,942,472

NONREVERSIBLE STEERING MECHANISM Filed April 4, 1928 3 Sheetgesheet 2 Jan. 9, 1934. F. c. cRAw.

NONREVERSIBLE STEERNG MECHANISM s sheets-'Sheet s Filed April, 4. 1928 pins project through the openings in the plate 19, the pins 28 passing through the openings 21 and the pins 29 through the openings 22. These pins are somewhat smaller in diameter than the diameter of the openings so as to permit a limited turning movement of the plate 27 relative to the plate 19. The locking pawls '23 and 24 are so lo-A cated with respect to the openings 21 and 22`and cesses in the pawls so that the springs will be heldin position. It will be noted `the casing 31 is open at one side but this open side is closed by a suitable cap 32 held by screws or bolts 33..

' In operation the outer free or curved ends 23 and 24 are normally in engagement with the inner surface of the wall of the casing 31. 'If now the shaft 13 should be turned to the left or counterclockwise, as viewed in Fig. 2, by the steering wheel, the pins 28 and 29 will first move in the openings 21 and 22 toward the left side of these openings to engage the same. During this operation the pins 29 will engage the sides of the pawls 24 and will swing their free outer ends away from the wall of the casing 31, as indicated vin Fig. 2, although the amount of movement is exaggerated in the drawing to more clearly show the operation. AWhen the pins 28 and 29 engage the side walls of the opening 21 and 22 in the plate 19 further movement of the shaft 13 and plate 27 will, through the pins 28 and 29, shift the plate-l 19 and with it the worm 14 which will operate the crank 17 to shift the front wheels of the car. The

pawls 23A during this movement would merely slide free on the inner surface of the casing 31 and will lnot interfere with the operation o f the elements. If the plate 27 and shaft 13 are turned clockwise,

as viewed in Fig. 2, thepins 28 and v29 will swing in the, opposite direction against the opposite side walls of the'openings '21 and 22 to swing the plate 19 in the opposite direction, and through the worm and crank will swing the front wheels in the o'pposite direction. Duringy this movement the pawls '24 will slide freely o n the inner wall of the casing while the pawls 23 will be released by the pins 21. It will thus be seen the locking pawls do not interfere in any way with the operation of the front wheels of the car for steering purposes from the hand steering wheel.

Should, however.- one of the' frontwheels of the car hit an obstruction, a rut, or `should off the side vof vthe road into mud, sand,v or soft earth, and therefore," tend to swing laterally, it

A' wm tend to tum the crank 1v and through the.

gearing turn the shaft 13 and the steering wheel. Itnmight jerk lit from the hands 'of the driver causing him to lose ,control provided such move- 'ment were permitted. The-locking mechanism shown, however, will prevent this result. As soon as the force' tends to turn the worm 14 it will tend to tur'n. the plate 19 which is rigidly attached to the worm, and if plate 19 should turn to the right, as viewed in Fig. 2, the free outer curved end of the pawls 23 will be immediately clamped against the inner wall of the casing -31 and will prevent any further movement. This is because the portion of. this surface adjacent the right hand edge ofthe upper pawl 23 or the left hand edge of the lower pawl 23 is eccentric to the pivot pins 25, and so as the'lpawl hub 43 in which the curved tends to swing about this pivot its outer end: will immediately clamp against the outerI wall ing on the wheels themselves, and they are held in the position in which they are placed by operation of. the hand steering' wheel, but this locking means lin no way interferes with the steering operation by the hand steering wheel. Referring t'o Figs. 3, 4 and 5,11 have shown the locking means applied to the steering column immediately under the hand steering wheel 34 of which only the hub and spokes are shown. The'locking mechanism is'also of a somewhat differentconstruction from that shown in Figs. 'l' and 2. The shaft 13 is enclosed by the steering column 35 which, of course, is rigidly mounted in the car. Rigidly secured tothis column as by a key 36, or other suitable means is a casing 37 open at its upper end which' is closed by a cap or plate 38. This lplate corresponds to and has substantially' the same function as the plate 27 in the form shown in Figs. l and 2 and is mounted loosely on the shaft 13. It has an extension 39 on which the hand steering wheel 34 is mounted and to which it is rigidly secured eitherby shrinkingit onto this extension or by a key 40.

Within the casing 3': and rigidly secured to the shaft 13 as by `iieans of a key 41, or by shrinking onto the aft, isa plate 42 'which has a hub 43..secur to the shaft 13. This plate has vopenings orfnotches 44 and 45substantially diametrically oppositely spaced to receive extensions 46 and 47 respectively carried bythe cap or plate 38. The openings or notches arel somewhat wider than the extensions to permit limited relative turning movement between the plates 38 and 42. Also pivotally connected t0 the plate 42 are the pawls 48 and 49 arranged in two opposedA pairs, .and as will be seen from Fig. 4 the pawls 49 are reversed in position from the pawls 48. A convenient means of mounting these pawls is to provide curved recesses in the inner ends v50 of the pawls are seated and on which they'may turn.v In` -their 'outer or freerends the 'pawls may carry circular clamping rods or lugs 51. As in thefirst form springs 52 are mounted between each set of pawls'48 and 49 tending to separate 'their free ends by swingingv them about their pivotal mountinss.

The operation of this construction is substantially the same as that shown in Figs. 1 and 2. If the hand steering wheel is Vturned to the left as viewed from the drivers position, or clockrecesses 44 theywill engage the. paw1s.48 and los casing. If the steering wheel is turned in the opposite direction, or counterclockwise as viewed in Figs. 4 and 5, the lugs 47 will release the pawls 49 in the same manner while the lugs 48 y will slide along the inner wall of the casing,

the plate 42 being rotated in the opposite direction or to the left by engagement of the extensions 46 and '47 with the opposite sides of the recesses 44 and 45.

Should, however, the shaft 13 tend to turn uncle.` action of the front wheels of the car clockwise or to the right, as viewed in Fig. 4, pawls 48 will immediately clamp against the casing 37 and lock the shaft from further movement and prevent this turning movement being transmitted to the hand steering wheel. If the shaft 13 tends to turn to the left or counterclockwise, as viewed in Fig. 4, it will immediately be locked by the pawls 49. This is because the clamping lugs or rods 51 are arranged so that they will swing outwardly about the pivots of the pawls. f

Referring to Figs. 6, 7 and 8, I have shown a locking mechanism substantially 'the same as that shown in Figs. 1 and 2 but as applied to the short shaft 16 instead of the steering wheel shaft'13. 1n this arrangement the worm 53 is rigid on the shaft 13 and meshes with a worm Wheel 54 rigid on an element 55 which is loose on the shaft 16. This worm wheel may be forced onto a hub or reduced portion 56 on this element. Keyed to the shaft 16 or otherwise rigidly secured thereto as by forcing it on the shaft is the plate 57 provided with two sets of openings 58 and 59 therein which correspond to the openings 21 and 22 in the form shown in Figs. 1 and 2, the plate 57 corresponding tc the plate 19 in the iirst form while the member 55 corresponds to the plate 27 in the rst form.

Pressed into the member 55 are pins 66 and 61 extending into the openings 58 and 59 respectively and of somewhat smaller diameter than these openings to permit a slight turning movement between the member 55 and the plate 57.-

Mounted on the plate 57 are two sets of pawls 62 and 63 pivoted on the pivot pins 64 pressed into the plate 57, and between each set of pawls 62 and63 is a spring 65 tending to separate their free ends. These pawls correspond to the pawls 23 and 24 of the rst form and are operated by the pins 60 and A61 exactly the same as are the pawls 23 and 24 operated by the pins 28 and 29 of the rst form so that'steering through this device is the same as that of the rst form. If the shaft. 16 is turned from the front wheels of the car these pawls 62 and 63 lock against the inner surface of the casing 66 the same as described in connection with the other forms. This operation is clearly shown in Fig. 8 where if the shaft 16 tendsto turn the plate 57 to the right the pawl 63 will immediately lock against the casing 66, and if the shaft 16 tends to turn the plate 57 to the left pawls 62 will immediately lock against the casing.

Referring to Figs. 10, 11 and 12, the form of device shown in these figures is substantially the same as that shown in Figs. 3, 4 and 5, but it is designed for arrangement o n the shaft 13 operated by the worm 53 and on which the crank 17 is mounted. In this arrangement the worm gear 67 is loose on the shaft 13 and a driven member or plate 68 is rigid on the shaft 13 to which it may be secured by a key 69, or as is the usual practice is shrunk onto this shaft. This plate 68 corresponds to plate 42 of Figs. 3, 4 and5 and has openings or notches 70 and 71'therein. The worm'gear 67 has laterally extending lugs 72 and 73 projecting hito openings or notches 70 and 71 the casing 66 in Figs. 6, 7 and 8. It will be noted v that this casing is open at one side to permit insertion or removal of the elements and is closed by the cap or plate 77. The pawls 75 and 76 may have their` outer ends curved to clamp against the casing similar to the pawls shown in Figs. 2, 6 and 8.or they may have the curved holding or clamping portions 51 the same as the pawls shown in Fig. 4. They are also held against the surface of the casing by the springs 52 the same as in the other forms. This form of device operates the same as the form shown in Figs. 3, 4 and 5 except for the difference in location. That is, the lugs 72 and'73 unlock thellocking pawls 75 and 76 respectively when the worm gear 67 is operated from the hand steering wheel and the lugs then drive the plate 68 to operate the shaft 13 and steer the iront Wheels of the car. lf the tendency to turn the shaft 13 comes from the front wheels of the car the pavfls 75 and 76, depending in which direction the shaft 10 is to turn, immediately lock against the inner surface of the casing and prevent the front wheels swinging out of position. l

It will be apparent from the foregoing description that the device may be made of simple and rugged construction, and therefore, will he effective and reliable in operation and not easily gotten out of order. It is not a complicated construction and requires comparatively small space on the steering mechanism. It eiecfively locks the front wheels in whatever position the hand steering wheel places them, and they can only be changed by this steering Wheel. Also this device does not interfere with the steering in the usual manner as the steering device turns as freely and easily in either direction as it would without this attachment, andthe hands can be removed from the steering wheel Without dangerof the front wheels oi the car changing position. Further, neither the front wheels of the car nor the steering Wheel will shimmy or vibrate. Consequently, it is an extremely safe and easily operated steering device. It is io be noted that the drive from the steering wheel is direct and not through the locking pawls, and therefore, in case of excessive wear or any damage to this attachment the Whole steering assembly, as far as the operation of the front wheels of the car lfrom the steering Wheel is concerned, will operate the same as before and the car can thus be operated the same as if this device had not been attached. It while running a tire should blow out the front wheels would remain in set positions and the operator would feel no jerk on the steering wheel. The 'same would be true if a front wheel struck an obstruction or depression in the road or if they ran olf In running over rough' roads or ruts neither the front wheels nor the steering wheels will wobble v all this there ismuch less Therefore, in view of danger of the operator car. vWith this device there or be affected in any way.

losing control of the is much less wear on the lworm andworm gear due to there being no vibration of the bali arm or crank, and the operator is not required to continually grip the steering wheel while driving .and he can, therefore, drive much longer and further Wihout fatigue.

Having thus set forth the nature of my invene tion, whatI claim is:

In a device of the character' described, a shaft, a. plate secured to the shaft having two pairs o! spaced openings therein and also having diametricaily opposite pairs of curved recesses opening outwardly with each pair of recesses between away from each other to engage 'a pair of openings.

a driving member free on the shaft and having two pairs of rigid extensions projecting into said openings and o! less width than the openingsso as to have limited movement therein but provide a positive driving connection between the driving member and the plate, a stationary casing, two pairs of pawls having lrounded ends seated in said recesses and located 

